At present, a wireless mobile communications network in which multiple radio access technologies and standards are complementary provides a ubiquitous information communications service for a user, and a user terminal can be freely switched between multiple different wireless mobile communications networks. In a wireless communications system, when moving from a current network in which the user terminal is located to a target network, the user terminal needs to perform network switching, where the target network refers to a next communications network to which the user terminal moves. In the prior art, after network switching occurs, an application program that is run on the user terminal and needs to perform network communication is run according to a network status of the target network by using a parameter that adapts to the network status. This switching manner usually causes that the application program that is run on the user terminal and needs to perform network communication is not smoothly switched.